Technical Field
The present disclosure relates to the touch control field, more particularly, to a self-capacitance in-cell touch screen and a method of manufacturing the same, and it also relates to a liquid crystal display including the in-cell touch screen.
Background Art
As an input media, a touch display screen is the simplest and most convenient human-machine interaction means, and thus, the touch display is more and more widely used in various electronic products. Based on different operation theories and media for transmitting information, the touch screen products are classified into four types: infrared touch screens, capacitance touch screens, resistance touch screens, and surface acoustic wave (SAW) touch screens, wherein the capacitance touch screens become the main-stream touch screen technique nowadays due to the advantages such as long life, high light transmittance, supporting multi-point touch control, etc. The capacitance touch screens include surface capacitance type and projective capacitance type, wherein the projective capacitance touch screens further include self-capacitance type and mutual capacitance type. Regarding self-capacitance touch structure, since the accuracy and signal-noise ratio of the touch induction thereof are higher, it is preferred by various panel factories.
At present, the self-capacitance touch structure realizes the function of detecting a position touched by a finger according to a self-capacitance theory with the details as follows: a plurality of touch control sensing electrodes are disposed in the touch screen structure, the capacitance sensed by respective touch sensing electrodes are a constant value when a human body does not touch the screen, while when the human body touches the screen, the capacitance sensed by the touch sensing electrode at the touched position is influenced by the human body, and a touch control detection chip may determine a touch-control position by detecting capacitance value changes of respective touch control sensing electrodes during a touch control period.
FIG. 1 is a schematic view illustrating an electrode distribution of existing self-capacitance touch screen structure. As shown in FIG. 1, the self-capacitance touch screen structure includes an touch control sensing electrode 7 arranged in array, each of which requires to be connected with the touch control detection chip (not shown) through a separated metal connection line 5. The touch sensing electrode 7 and the metal connection line 5 are disposed on different layers with insulation layers (not shown) isolating them, and the touch sensing electrode 7 are electrically connected with corresponding metal connection line 5 through a via hole. In particular, regarding a column of touch control sensing electrodes, each metal connection line is not connected to a front touch control sensing electrode before being connected to corresponding touch control sensing electrode, and not connected to a rear touch control sensing electrode after being connected to the corresponding touch control sensing electrode.
In the self-capacitance in-cell touch screen, the touch control sensing electrode and the metal connection line in the touch screen structure are commonly directly disposed on an array substrate or a color filter substrate. FIG. 2 is a local structural schematic view illustrating an array substrate having the touch screen structure. As shown in FIG. 2, the array substrate includes a glass substrate 1, a thin film transistor 2 disposed on the glass substrate 1, a pixel electrode 3 electrically connected to the thin film transistor 2, and a planarizing layer 4 interposed between the pixel electrode 3 and the thin film transistor 2. The touch screen structure is disposed on the planarizing layer with the details as follows: firstly, the metal connection line 5 is formed on the planarizing layer 4; then a first insulation layer 6 is covered on the metal connection line 5; the touch control sensing electrode 7 is further disposed on the first insulation layer 6 and is electrically connected to the metal connection line 5 through the via hole; and finally, a second insulation layer 8 is covered on the touch control sensing electrode 7. The first and second insulation layers 6 and 8 are interposed between the planarizing layer 4 and the pixel electrode 3 in sequence. The pixel electrode 3 is electrically connected to the thin film transistor 2 (i.e., connected to a source electrode or a drain electrode of the thin film transistor 2) though via holes disposed in the planarizing layer 4, and the first and second insulation layers 6 and 8. The touch control sensing electrode 7 is further configured as a common electrode to transfer a common voltage (Vcom) and a touch scan signal by time-sharing during a period of displaying one frame image.
In the array substrate with the above structure, the planarizing layer 4 is made of an organic material, and the metal connection line 5 is made of a metal material. When manufacturing the metal connection line 5 on the planarizing layer 4 by using a deposition process, the high temperature in the deposition process may cause the planarizing layer 4 to give off gases, while since the metal connection line 5 has a relatively small width and a relatively great thickness, the adhesion between metal connection line 5 and the planarizing layer 4 may be weak, which may be easy to cause the defect of falling off, resulting in an influence on the quality of the product.